In the case of presence of an obstruction, it is generally easy to form a visual blind area. An observer cannot obtain view of the part obstructed by the obstruction so as to easily cause kinds of problems. For example, columns of windshields in various driving cabs may form visual blind area, and car doors may also block view of the observer. In recent years, due to development of smart glasses, it is possible to see through objects. However, current smart glasses can only be used for seeing through the inner structure of an object, rather than the whole object, such as an obstruction, and the object can be seen through only when the image of the inner structure of the object is known in advance.